It is common in various growing environments to use a growth bed other than dirt and soil. For example, it is recognized that acid or desert soils usually cannot sustain any appreciable growth. Also, many soils may adversely affect plant growth owing to such factors as nutrient depletion, chemical poisoning, improper pH adjustment, or even poor soil consistency. As a result, many green houses use a non-soil growth bed to obtain better pH control of growing conditions, ease handling of the growth bed since heavy soil is not used, provide an enhanced air and liquid permeability, and minimize harmful bacterial growth.
Many different varieties of growth beds have been produced and commercialized. For example, U.S. Pat. Nos. 4,292,760, and 4,292,761 to Krave disclose a porous, urethane substrate used as a bed for sprouting seeds. U.S. Pat. No. 4,424,645 to Rannali discloses the use of compressed peat pellets packaged in a flexible, rollable container to facilitate handling thereof as well as mineral wool fibers which are commonly sold in the trade under the name Rockwool. In addition, mixtures of mineral wool fibers with peat, and even dried peat and styrofoam beads having dry, pulverized fertilizer added therein have been used as a growth bed.
Inherent limitations of these growth beds have restricted their application. For example, a combination of peat and other products may provide a growth bed having sufficient nutrients and air-liquid permeability. Nevertheless, peat is nonhomogeneous, prone to harmful bacterial growth, and difficult to stabilize for pH adjustment. In addition, peat is cumbersome to transport even when dried and compressed within a container or grow receptacle of some type since the amount which the peat can be compressed is limited.
Mineral wool fibers, on the other hand, provide a growth bed which possesses acceptable air and fluid permeability which makes it practical for insertion into a plastic bag, which commonly is referred to in the trade as a "grow bag."Holes can be punched in the bag and the roots of a plant or a plant positioned in a block of urethane or soil inserted therein. To sustain growth, nutrient laden water and sometimes bacterial growth inhibitors or other plant growth stimulators are added.
As compared to growth beds of peat or combinations of peat, soil, urethane or other growth bed materials, mineral wool fibers are homogenous and can be added to a "grow bag" in measured amounts for providing an established density and volume which aids in maintaining a constant air and fluid permeability. However, even with these benefits, the use of mineral wool fibers as a growth bed are limited. Mineral wool fibers do not "wick" water adequately and currently the use of such fibers has become the subject of health concerns. Also, these fibers are heavy and cannot be compressed to facilitate shipping and handling. This makes transport particularly to those overseas countries which have a need for alternative growth beds costly, burdensome and impractical.
It is accordingly an object of the present invention to provide a growth bed formed from a bedding of crimped textile fibers which retains high loft to provide open spaces around the fibers to allow for optimum air for proper root development and plant growth.
It is a further object of this invention to provide a growth bed which is readily compressible as for compact shipment.
It is another object of this invention to provide a growth bed which adequately receives and retains water throughout.
Further and more specific objects and advantages of the invention will become apparent as the description proceeds.